<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div id="app">
    <input type="text" v-focus>
  </div>

  <div id="app2">
    <input type="text" v-focus>
  </div>
  <script src="lib/vue.js"></script>
  <script>
    // 自定义局部指令
    new Vue({
      el: '#app',
      data: {},
      directives: {
        focus: {
          inserted (el) {
            el.focus();
          }
        }
      }
    });

    new Vue({
      el: '#app2'
    });
  </script>
</body>
</html>